1. Field
The present disclosure relates generally to vehicles and, in particular, to inert gas systems used in fuel tanks in vehicles. Still more particularly, the present disclosure relates to a method and apparatus for managing inert gas in a fuel tank of an aircraft.
2. Background
Fuel tanks in vehicles carry fuel that is used to operate the engines of a vehicle. The fuel is flammable in the presence of oxygen or air. When fuel is used, the level of fuel decreases. This decrease in the level of fuel results in a space increasing in size above the level of fuel in the fuel tank. The space above the fuel may contain air and fuel vapors. This space may be referred to as an “ullage”.
Increased safety for fuel tanks may be provided through the use of an inert gas system. The inert gas system may generate and distribute an inert gas to reduce the oxygen content that may be present in the fuel tanks. In particular, the space above the surface of the fuel in the fuel tank is filled with an inert gas.
The inert gas displaces air that contains oxygen in the fuel tank. The inert gas may also displace fuel vapors and other elements. This process is called “inerting”. The inert gas reduces the oxygen content in this space in a manner that reduces a possibility of a combustion event, including ignition, detonation, or deflagration. The combustion event may be the combustion of the fuel, fuel vapor, or both.
The inert gas is introduced using the inert gas system. These systems, however, may be more complex and heavier than desired based on the efficiency of the distribution system in an inert gas system.
Therefore, it would be advantageous to have a method and apparatus that takes into account at least some of the issues discussed above, as well as possibly other issues.